xref: /openbmc/linux/drivers/i2c/busses/i2c-stm32f7.c (revision 09a4f6f5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for STMicroelectronics STM32F7 I2C controller
4  *
5  * This I2C controller is described in the STM32F75xxx and STM32F74xxx Soc
6  * reference manual.
7  * Please see below a link to the documentation:
8  * http://www.st.com/resource/en/reference_manual/dm00124865.pdf
9  *
10  * Copyright (C) M'boumba Cedric Madianga 2017
11  * Copyright (C) STMicroelectronics 2017
12  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
13  *
14  * This driver is based on i2c-stm32f4.c
15  *
16  */
17 #include <linux/clk.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/i2c.h>
21 #include <linux/i2c-smbus.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/iopoll.h>
25 #include <linux/mfd/syscon.h>
26 #include <linux/module.h>
27 #include <linux/of.h>
28 #include <linux/of_address.h>
29 #include <linux/of_platform.h>
30 #include <linux/platform_device.h>
31 #include <linux/pinctrl/consumer.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pm_wakeirq.h>
34 #include <linux/regmap.h>
35 #include <linux/reset.h>
36 #include <linux/slab.h>
37 
38 #include "i2c-stm32.h"
39 
40 /* STM32F7 I2C registers */
41 #define STM32F7_I2C_CR1				0x00
42 #define STM32F7_I2C_CR2				0x04
43 #define STM32F7_I2C_OAR1			0x08
44 #define STM32F7_I2C_OAR2			0x0C
45 #define STM32F7_I2C_PECR			0x20
46 #define STM32F7_I2C_TIMINGR			0x10
47 #define STM32F7_I2C_ISR				0x18
48 #define STM32F7_I2C_ICR				0x1C
49 #define STM32F7_I2C_RXDR			0x24
50 #define STM32F7_I2C_TXDR			0x28
51 
52 /* STM32F7 I2C control 1 */
53 #define STM32F7_I2C_CR1_PECEN			BIT(23)
54 #define STM32F7_I2C_CR1_SMBHEN			BIT(20)
55 #define STM32F7_I2C_CR1_WUPEN			BIT(18)
56 #define STM32F7_I2C_CR1_SBC			BIT(16)
57 #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
58 #define STM32F7_I2C_CR1_TXDMAEN			BIT(14)
59 #define STM32F7_I2C_CR1_ANFOFF			BIT(12)
60 #define STM32F7_I2C_CR1_ERRIE			BIT(7)
61 #define STM32F7_I2C_CR1_TCIE			BIT(6)
62 #define STM32F7_I2C_CR1_STOPIE			BIT(5)
63 #define STM32F7_I2C_CR1_NACKIE			BIT(4)
64 #define STM32F7_I2C_CR1_ADDRIE			BIT(3)
65 #define STM32F7_I2C_CR1_RXIE			BIT(2)
66 #define STM32F7_I2C_CR1_TXIE			BIT(1)
67 #define STM32F7_I2C_CR1_PE			BIT(0)
68 #define STM32F7_I2C_ALL_IRQ_MASK		(STM32F7_I2C_CR1_ERRIE \
69 						| STM32F7_I2C_CR1_TCIE \
70 						| STM32F7_I2C_CR1_STOPIE \
71 						| STM32F7_I2C_CR1_NACKIE \
72 						| STM32F7_I2C_CR1_RXIE \
73 						| STM32F7_I2C_CR1_TXIE)
74 #define STM32F7_I2C_XFER_IRQ_MASK		(STM32F7_I2C_CR1_TCIE \
75 						| STM32F7_I2C_CR1_STOPIE \
76 						| STM32F7_I2C_CR1_NACKIE \
77 						| STM32F7_I2C_CR1_RXIE \
78 						| STM32F7_I2C_CR1_TXIE)
79 
80 /* STM32F7 I2C control 2 */
81 #define STM32F7_I2C_CR2_PECBYTE			BIT(26)
82 #define STM32F7_I2C_CR2_RELOAD			BIT(24)
83 #define STM32F7_I2C_CR2_NBYTES_MASK		GENMASK(23, 16)
84 #define STM32F7_I2C_CR2_NBYTES(n)		(((n) & 0xff) << 16)
85 #define STM32F7_I2C_CR2_NACK			BIT(15)
86 #define STM32F7_I2C_CR2_STOP			BIT(14)
87 #define STM32F7_I2C_CR2_START			BIT(13)
88 #define STM32F7_I2C_CR2_HEAD10R			BIT(12)
89 #define STM32F7_I2C_CR2_ADD10			BIT(11)
90 #define STM32F7_I2C_CR2_RD_WRN			BIT(10)
91 #define STM32F7_I2C_CR2_SADD10_MASK		GENMASK(9, 0)
92 #define STM32F7_I2C_CR2_SADD10(n)		(((n) & \
93 						STM32F7_I2C_CR2_SADD10_MASK))
94 #define STM32F7_I2C_CR2_SADD7_MASK		GENMASK(7, 1)
95 #define STM32F7_I2C_CR2_SADD7(n)		(((n) & 0x7f) << 1)
96 
97 /* STM32F7 I2C Own Address 1 */
98 #define STM32F7_I2C_OAR1_OA1EN			BIT(15)
99 #define STM32F7_I2C_OAR1_OA1MODE		BIT(10)
100 #define STM32F7_I2C_OAR1_OA1_10_MASK		GENMASK(9, 0)
101 #define STM32F7_I2C_OAR1_OA1_10(n)		(((n) & \
102 						STM32F7_I2C_OAR1_OA1_10_MASK))
103 #define STM32F7_I2C_OAR1_OA1_7_MASK		GENMASK(7, 1)
104 #define STM32F7_I2C_OAR1_OA1_7(n)		(((n) & 0x7f) << 1)
105 #define STM32F7_I2C_OAR1_MASK			(STM32F7_I2C_OAR1_OA1_7_MASK \
106 						| STM32F7_I2C_OAR1_OA1_10_MASK \
107 						| STM32F7_I2C_OAR1_OA1EN \
108 						| STM32F7_I2C_OAR1_OA1MODE)
109 
110 /* STM32F7 I2C Own Address 2 */
111 #define STM32F7_I2C_OAR2_OA2EN			BIT(15)
112 #define STM32F7_I2C_OAR2_OA2MSK_MASK		GENMASK(10, 8)
113 #define STM32F7_I2C_OAR2_OA2MSK(n)		(((n) & 0x7) << 8)
114 #define STM32F7_I2C_OAR2_OA2_7_MASK		GENMASK(7, 1)
115 #define STM32F7_I2C_OAR2_OA2_7(n)		(((n) & 0x7f) << 1)
116 #define STM32F7_I2C_OAR2_MASK			(STM32F7_I2C_OAR2_OA2MSK_MASK \
117 						| STM32F7_I2C_OAR2_OA2_7_MASK \
118 						| STM32F7_I2C_OAR2_OA2EN)
119 
120 /* STM32F7 I2C Interrupt Status */
121 #define STM32F7_I2C_ISR_ADDCODE_MASK		GENMASK(23, 17)
122 #define STM32F7_I2C_ISR_ADDCODE_GET(n) \
123 				(((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17)
124 #define STM32F7_I2C_ISR_DIR			BIT(16)
125 #define STM32F7_I2C_ISR_BUSY			BIT(15)
126 #define STM32F7_I2C_ISR_PECERR			BIT(11)
127 #define STM32F7_I2C_ISR_ARLO			BIT(9)
128 #define STM32F7_I2C_ISR_BERR			BIT(8)
129 #define STM32F7_I2C_ISR_TCR			BIT(7)
130 #define STM32F7_I2C_ISR_TC			BIT(6)
131 #define STM32F7_I2C_ISR_STOPF			BIT(5)
132 #define STM32F7_I2C_ISR_NACKF			BIT(4)
133 #define STM32F7_I2C_ISR_ADDR			BIT(3)
134 #define STM32F7_I2C_ISR_RXNE			BIT(2)
135 #define STM32F7_I2C_ISR_TXIS			BIT(1)
136 #define STM32F7_I2C_ISR_TXE			BIT(0)
137 
138 /* STM32F7 I2C Interrupt Clear */
139 #define STM32F7_I2C_ICR_PECCF			BIT(11)
140 #define STM32F7_I2C_ICR_ARLOCF			BIT(9)
141 #define STM32F7_I2C_ICR_BERRCF			BIT(8)
142 #define STM32F7_I2C_ICR_STOPCF			BIT(5)
143 #define STM32F7_I2C_ICR_NACKCF			BIT(4)
144 #define STM32F7_I2C_ICR_ADDRCF			BIT(3)
145 
146 /* STM32F7 I2C Timing */
147 #define STM32F7_I2C_TIMINGR_PRESC(n)		(((n) & 0xf) << 28)
148 #define STM32F7_I2C_TIMINGR_SCLDEL(n)		(((n) & 0xf) << 20)
149 #define STM32F7_I2C_TIMINGR_SDADEL(n)		(((n) & 0xf) << 16)
150 #define STM32F7_I2C_TIMINGR_SCLH(n)		(((n) & 0xff) << 8)
151 #define STM32F7_I2C_TIMINGR_SCLL(n)		((n) & 0xff)
152 
153 #define STM32F7_I2C_MAX_LEN			0xff
154 #define STM32F7_I2C_DMA_LEN_MIN			0x16
155 enum {
156 	STM32F7_SLAVE_HOSTNOTIFY,
157 	STM32F7_SLAVE_7_10_BITS_ADDR,
158 	STM32F7_SLAVE_7_BITS_ADDR,
159 	STM32F7_I2C_MAX_SLAVE
160 };
161 
162 #define STM32F7_I2C_DNF_DEFAULT			0
163 #define STM32F7_I2C_DNF_MAX			16
164 
165 #define STM32F7_I2C_ANALOG_FILTER_ENABLE	1
166 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MIN	50	/* ns */
167 #define STM32F7_I2C_ANALOG_FILTER_DELAY_MAX	260	/* ns */
168 
169 #define STM32F7_I2C_RISE_TIME_DEFAULT		25	/* ns */
170 #define STM32F7_I2C_FALL_TIME_DEFAULT		10	/* ns */
171 
172 #define STM32F7_PRESC_MAX			BIT(4)
173 #define STM32F7_SCLDEL_MAX			BIT(4)
174 #define STM32F7_SDADEL_MAX			BIT(4)
175 #define STM32F7_SCLH_MAX			BIT(8)
176 #define STM32F7_SCLL_MAX			BIT(8)
177 
178 #define STM32F7_AUTOSUSPEND_DELAY		(HZ / 100)
179 
180 /**
181  * struct stm32f7_i2c_regs - i2c f7 registers backup
182  * @cr1: Control register 1
183  * @cr2: Control register 2
184  * @oar1: Own address 1 register
185  * @oar2: Own address 2 register
186  * @tmgr: Timing register
187  */
188 struct stm32f7_i2c_regs {
189 	u32 cr1;
190 	u32 cr2;
191 	u32 oar1;
192 	u32 oar2;
193 	u32 tmgr;
194 };
195 
196 /**
197  * struct stm32f7_i2c_spec - private i2c specification timing
198  * @rate: I2C bus speed (Hz)
199  * @fall_max: Max fall time of both SDA and SCL signals (ns)
200  * @rise_max: Max rise time of both SDA and SCL signals (ns)
201  * @hddat_min: Min data hold time (ns)
202  * @vddat_max: Max data valid time (ns)
203  * @sudat_min: Min data setup time (ns)
204  * @l_min: Min low period of the SCL clock (ns)
205  * @h_min: Min high period of the SCL clock (ns)
206  */
207 struct stm32f7_i2c_spec {
208 	u32 rate;
209 	u32 fall_max;
210 	u32 rise_max;
211 	u32 hddat_min;
212 	u32 vddat_max;
213 	u32 sudat_min;
214 	u32 l_min;
215 	u32 h_min;
216 };
217 
218 /**
219  * struct stm32f7_i2c_setup - private I2C timing setup parameters
220  * @speed_freq: I2C speed frequency  (Hz)
221  * @clock_src: I2C clock source frequency (Hz)
222  * @rise_time: Rise time (ns)
223  * @fall_time: Fall time (ns)
224  * @dnf: Digital filter coefficient (0-16)
225  * @analog_filter: Analog filter delay (On/Off)
226  * @fmp_clr_offset: Fast Mode Plus clear register offset from set register
227  */
228 struct stm32f7_i2c_setup {
229 	u32 speed_freq;
230 	u32 clock_src;
231 	u32 rise_time;
232 	u32 fall_time;
233 	u8 dnf;
234 	bool analog_filter;
235 	u32 fmp_clr_offset;
236 };
237 
238 /**
239  * struct stm32f7_i2c_timings - private I2C output parameters
240  * @node: List entry
241  * @presc: Prescaler value
242  * @scldel: Data setup time
243  * @sdadel: Data hold time
244  * @sclh: SCL high period (master mode)
245  * @scll: SCL low period (master mode)
246  */
247 struct stm32f7_i2c_timings {
248 	struct list_head node;
249 	u8 presc;
250 	u8 scldel;
251 	u8 sdadel;
252 	u8 sclh;
253 	u8 scll;
254 };
255 
256 /**
257  * struct stm32f7_i2c_msg - client specific data
258  * @addr: 8-bit or 10-bit slave addr, including r/w bit
259  * @count: number of bytes to be transferred
260  * @buf: data buffer
261  * @result: result of the transfer
262  * @stop: last I2C msg to be sent, i.e. STOP to be generated
263  * @smbus: boolean to know if the I2C IP is used in SMBus mode
264  * @size: type of SMBus protocol
265  * @read_write: direction of SMBus protocol
266  * SMBus block read and SMBus block write - block read process call protocols
267  * @smbus_buf: buffer to be used for SMBus protocol transfer. It will
268  * contain a maximum of 32 bytes of data + byte command + byte count + PEC
269  * This buffer has to be 32-bit aligned to be compliant with memory address
270  * register in DMA mode.
271  */
272 struct stm32f7_i2c_msg {
273 	u16 addr;
274 	u32 count;
275 	u8 *buf;
276 	int result;
277 	bool stop;
278 	bool smbus;
279 	int size;
280 	char read_write;
281 	u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4);
282 };
283 
284 /**
285  * struct stm32f7_i2c_dev - private data of the controller
286  * @adap: I2C adapter for this controller
287  * @dev: device for this controller
288  * @base: virtual memory area
289  * @complete: completion of I2C message
290  * @clk: hw i2c clock
291  * @bus_rate: I2C clock frequency of the controller
292  * @msg: Pointer to data to be written
293  * @msg_num: number of I2C messages to be executed
294  * @msg_id: message identifiant
295  * @f7_msg: customized i2c msg for driver usage
296  * @setup: I2C timing input setup
297  * @timing: I2C computed timings
298  * @slave: list of slave devices registered on the I2C bus
299  * @slave_running: slave device currently used
300  * @backup_regs: backup of i2c controller registers (for suspend/resume)
301  * @slave_dir: transfer direction for the current slave device
302  * @master_mode: boolean to know in which mode the I2C is running (master or
303  * slave)
304  * @dma: dma data
305  * @use_dma: boolean to know if dma is used in the current transfer
306  * @regmap: holds SYSCFG phandle for Fast Mode Plus bits
307  * @fmp_sreg: register address for setting Fast Mode Plus bits
308  * @fmp_creg: register address for clearing Fast Mode Plus bits
309  * @fmp_mask: mask for Fast Mode Plus bits in set register
310  * @wakeup_src: boolean to know if the device is a wakeup source
311  * @smbus_mode: states that the controller is configured in SMBus mode
312  * @host_notify_client: SMBus host-notify client
313  */
314 struct stm32f7_i2c_dev {
315 	struct i2c_adapter adap;
316 	struct device *dev;
317 	void __iomem *base;
318 	struct completion complete;
319 	struct clk *clk;
320 	unsigned int bus_rate;
321 	struct i2c_msg *msg;
322 	unsigned int msg_num;
323 	unsigned int msg_id;
324 	struct stm32f7_i2c_msg f7_msg;
325 	struct stm32f7_i2c_setup setup;
326 	struct stm32f7_i2c_timings timing;
327 	struct i2c_client *slave[STM32F7_I2C_MAX_SLAVE];
328 	struct i2c_client *slave_running;
329 	struct stm32f7_i2c_regs backup_regs;
330 	u32 slave_dir;
331 	bool master_mode;
332 	struct stm32_i2c_dma *dma;
333 	bool use_dma;
334 	struct regmap *regmap;
335 	u32 fmp_sreg;
336 	u32 fmp_creg;
337 	u32 fmp_mask;
338 	bool wakeup_src;
339 	bool smbus_mode;
340 	struct i2c_client *host_notify_client;
341 };
342 
343 /*
344  * All these values are coming from I2C Specification, Version 6.0, 4th of
345  * April 2014.
346  *
347  * Table10. Characteristics of the SDA and SCL bus lines for Standard, Fast,
348  * and Fast-mode Plus I2C-bus devices
349  */
350 static struct stm32f7_i2c_spec stm32f7_i2c_specs[] = {
351 	{
352 		.rate = I2C_MAX_STANDARD_MODE_FREQ,
353 		.fall_max = 300,
354 		.rise_max = 1000,
355 		.hddat_min = 0,
356 		.vddat_max = 3450,
357 		.sudat_min = 250,
358 		.l_min = 4700,
359 		.h_min = 4000,
360 	},
361 	{
362 		.rate = I2C_MAX_FAST_MODE_FREQ,
363 		.fall_max = 300,
364 		.rise_max = 300,
365 		.hddat_min = 0,
366 		.vddat_max = 900,
367 		.sudat_min = 100,
368 		.l_min = 1300,
369 		.h_min = 600,
370 	},
371 	{
372 		.rate = I2C_MAX_FAST_MODE_PLUS_FREQ,
373 		.fall_max = 100,
374 		.rise_max = 120,
375 		.hddat_min = 0,
376 		.vddat_max = 450,
377 		.sudat_min = 50,
378 		.l_min = 500,
379 		.h_min = 260,
380 	},
381 };
382 
383 static const struct stm32f7_i2c_setup stm32f7_setup = {
384 	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
385 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
386 	.dnf = STM32F7_I2C_DNF_DEFAULT,
387 	.analog_filter = STM32F7_I2C_ANALOG_FILTER_ENABLE,
388 };
389 
390 static const struct stm32f7_i2c_setup stm32mp15_setup = {
391 	.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
392 	.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
393 	.dnf = STM32F7_I2C_DNF_DEFAULT,
394 	.analog_filter = STM32F7_I2C_ANALOG_FILTER_ENABLE,
395 	.fmp_clr_offset = 0x40,
396 };
397 
398 static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask)
399 {
400 	writel_relaxed(readl_relaxed(reg) | mask, reg);
401 }
402 
403 static inline void stm32f7_i2c_clr_bits(void __iomem *reg, u32 mask)
404 {
405 	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
406 }
407 
408 static void stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev *i2c_dev, u32 mask)
409 {
410 	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, mask);
411 }
412 
413 static struct stm32f7_i2c_spec *stm32f7_get_specs(u32 rate)
414 {
415 	int i;
416 
417 	for (i = 0; i < ARRAY_SIZE(stm32f7_i2c_specs); i++)
418 		if (rate <= stm32f7_i2c_specs[i].rate)
419 			return &stm32f7_i2c_specs[i];
420 
421 	return ERR_PTR(-EINVAL);
422 }
423 
424 #define	RATE_MIN(rate)	((rate) * 8 / 10)
425 static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev,
426 				      struct stm32f7_i2c_setup *setup,
427 				      struct stm32f7_i2c_timings *output)
428 {
429 	struct stm32f7_i2c_spec *specs;
430 	u32 p_prev = STM32F7_PRESC_MAX;
431 	u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
432 				       setup->clock_src);
433 	u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
434 				       setup->speed_freq);
435 	u32 clk_error_prev = i2cbus;
436 	u32 tsync;
437 	u32 af_delay_min, af_delay_max;
438 	u32 dnf_delay;
439 	u32 clk_min, clk_max;
440 	int sdadel_min, sdadel_max;
441 	int scldel_min;
442 	struct stm32f7_i2c_timings *v, *_v, *s;
443 	struct list_head solutions;
444 	u16 p, l, a, h;
445 	int ret = 0;
446 
447 	specs = stm32f7_get_specs(setup->speed_freq);
448 	if (specs == ERR_PTR(-EINVAL)) {
449 		dev_err(i2c_dev->dev, "speed out of bound {%d}\n",
450 			setup->speed_freq);
451 		return -EINVAL;
452 	}
453 
454 	if ((setup->rise_time > specs->rise_max) ||
455 	    (setup->fall_time > specs->fall_max)) {
456 		dev_err(i2c_dev->dev,
457 			"timings out of bound Rise{%d>%d}/Fall{%d>%d}\n",
458 			setup->rise_time, specs->rise_max,
459 			setup->fall_time, specs->fall_max);
460 		return -EINVAL;
461 	}
462 
463 	if (setup->dnf > STM32F7_I2C_DNF_MAX) {
464 		dev_err(i2c_dev->dev,
465 			"DNF out of bound %d/%d\n",
466 			setup->dnf, STM32F7_I2C_DNF_MAX);
467 		return -EINVAL;
468 	}
469 
470 	/*  Analog and Digital Filters */
471 	af_delay_min =
472 		(setup->analog_filter ?
473 		 STM32F7_I2C_ANALOG_FILTER_DELAY_MIN : 0);
474 	af_delay_max =
475 		(setup->analog_filter ?
476 		 STM32F7_I2C_ANALOG_FILTER_DELAY_MAX : 0);
477 	dnf_delay = setup->dnf * i2cclk;
478 
479 	sdadel_min = specs->hddat_min + setup->fall_time -
480 		af_delay_min - (setup->dnf + 3) * i2cclk;
481 
482 	sdadel_max = specs->vddat_max - setup->rise_time -
483 		af_delay_max - (setup->dnf + 4) * i2cclk;
484 
485 	scldel_min = setup->rise_time + specs->sudat_min;
486 
487 	if (sdadel_min < 0)
488 		sdadel_min = 0;
489 	if (sdadel_max < 0)
490 		sdadel_max = 0;
491 
492 	dev_dbg(i2c_dev->dev, "SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n",
493 		sdadel_min, sdadel_max, scldel_min);
494 
495 	INIT_LIST_HEAD(&solutions);
496 	/* Compute possible values for PRESC, SCLDEL and SDADEL */
497 	for (p = 0; p < STM32F7_PRESC_MAX; p++) {
498 		for (l = 0; l < STM32F7_SCLDEL_MAX; l++) {
499 			u32 scldel = (l + 1) * (p + 1) * i2cclk;
500 
501 			if (scldel < scldel_min)
502 				continue;
503 
504 			for (a = 0; a < STM32F7_SDADEL_MAX; a++) {
505 				u32 sdadel = (a * (p + 1) + 1) * i2cclk;
506 
507 				if (((sdadel >= sdadel_min) &&
508 				     (sdadel <= sdadel_max)) &&
509 				    (p != p_prev)) {
510 					v = kmalloc(sizeof(*v), GFP_KERNEL);
511 					if (!v) {
512 						ret = -ENOMEM;
513 						goto exit;
514 					}
515 
516 					v->presc = p;
517 					v->scldel = l;
518 					v->sdadel = a;
519 					p_prev = p;
520 
521 					list_add_tail(&v->node,
522 						      &solutions);
523 					break;
524 				}
525 			}
526 
527 			if (p_prev == p)
528 				break;
529 		}
530 	}
531 
532 	if (list_empty(&solutions)) {
533 		dev_err(i2c_dev->dev, "no Prescaler solution\n");
534 		ret = -EPERM;
535 		goto exit;
536 	}
537 
538 	tsync = af_delay_min + dnf_delay + (2 * i2cclk);
539 	s = NULL;
540 	clk_max = NSEC_PER_SEC / RATE_MIN(setup->speed_freq);
541 	clk_min = NSEC_PER_SEC / setup->speed_freq;
542 
543 	/*
544 	 * Among Prescaler possibilities discovered above figures out SCL Low
545 	 * and High Period. Provided:
546 	 * - SCL Low Period has to be higher than SCL Clock Low Period
547 	 *   defined by I2C Specification. I2C Clock has to be lower than
548 	 *   (SCL Low Period - Analog/Digital filters) / 4.
549 	 * - SCL High Period has to be lower than SCL Clock High Period
550 	 *   defined by I2C Specification
551 	 * - I2C Clock has to be lower than SCL High Period
552 	 */
553 	list_for_each_entry(v, &solutions, node) {
554 		u32 prescaler = (v->presc + 1) * i2cclk;
555 
556 		for (l = 0; l < STM32F7_SCLL_MAX; l++) {
557 			u32 tscl_l = (l + 1) * prescaler + tsync;
558 
559 			if ((tscl_l < specs->l_min) ||
560 			    (i2cclk >=
561 			     ((tscl_l - af_delay_min - dnf_delay) / 4))) {
562 				continue;
563 			}
564 
565 			for (h = 0; h < STM32F7_SCLH_MAX; h++) {
566 				u32 tscl_h = (h + 1) * prescaler + tsync;
567 				u32 tscl = tscl_l + tscl_h +
568 					setup->rise_time + setup->fall_time;
569 
570 				if ((tscl >= clk_min) && (tscl <= clk_max) &&
571 				    (tscl_h >= specs->h_min) &&
572 				    (i2cclk < tscl_h)) {
573 					int clk_error = tscl - i2cbus;
574 
575 					if (clk_error < 0)
576 						clk_error = -clk_error;
577 
578 					if (clk_error < clk_error_prev) {
579 						clk_error_prev = clk_error;
580 						v->scll = l;
581 						v->sclh = h;
582 						s = v;
583 					}
584 				}
585 			}
586 		}
587 	}
588 
589 	if (!s) {
590 		dev_err(i2c_dev->dev, "no solution at all\n");
591 		ret = -EPERM;
592 		goto exit;
593 	}
594 
595 	output->presc = s->presc;
596 	output->scldel = s->scldel;
597 	output->sdadel = s->sdadel;
598 	output->scll = s->scll;
599 	output->sclh = s->sclh;
600 
601 	dev_dbg(i2c_dev->dev,
602 		"Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n",
603 		output->presc,
604 		output->scldel, output->sdadel,
605 		output->scll, output->sclh);
606 
607 exit:
608 	/* Release list and memory */
609 	list_for_each_entry_safe(v, _v, &solutions, node) {
610 		list_del(&v->node);
611 		kfree(v);
612 	}
613 
614 	return ret;
615 }
616 
617 static u32 stm32f7_get_lower_rate(u32 rate)
618 {
619 	int i = ARRAY_SIZE(stm32f7_i2c_specs);
620 
621 	while (--i)
622 		if (stm32f7_i2c_specs[i].rate < rate)
623 			break;
624 
625 	return stm32f7_i2c_specs[i].rate;
626 }
627 
628 static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev,
629 				    struct stm32f7_i2c_setup *setup)
630 {
631 	struct i2c_timings timings, *t = &timings;
632 	int ret = 0;
633 
634 	t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
635 	t->scl_rise_ns = i2c_dev->setup.rise_time;
636 	t->scl_fall_ns = i2c_dev->setup.fall_time;
637 
638 	i2c_parse_fw_timings(i2c_dev->dev, t, false);
639 
640 	if (t->bus_freq_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) {
641 		dev_err(i2c_dev->dev, "Invalid bus speed (%i>%i)\n",
642 			t->bus_freq_hz, I2C_MAX_FAST_MODE_PLUS_FREQ);
643 		return -EINVAL;
644 	}
645 
646 	setup->speed_freq = t->bus_freq_hz;
647 	i2c_dev->setup.rise_time = t->scl_rise_ns;
648 	i2c_dev->setup.fall_time = t->scl_fall_ns;
649 	setup->clock_src = clk_get_rate(i2c_dev->clk);
650 
651 	if (!setup->clock_src) {
652 		dev_err(i2c_dev->dev, "clock rate is 0\n");
653 		return -EINVAL;
654 	}
655 
656 	do {
657 		ret = stm32f7_i2c_compute_timing(i2c_dev, setup,
658 						 &i2c_dev->timing);
659 		if (ret) {
660 			dev_err(i2c_dev->dev,
661 				"failed to compute I2C timings.\n");
662 			if (setup->speed_freq <= I2C_MAX_STANDARD_MODE_FREQ)
663 				break;
664 			setup->speed_freq =
665 				stm32f7_get_lower_rate(setup->speed_freq);
666 			dev_warn(i2c_dev->dev,
667 				 "downgrade I2C Speed Freq to (%i)\n",
668 				 setup->speed_freq);
669 		}
670 	} while (ret);
671 
672 	if (ret) {
673 		dev_err(i2c_dev->dev, "Impossible to compute I2C timings.\n");
674 		return ret;
675 	}
676 
677 	dev_dbg(i2c_dev->dev, "I2C Speed(%i), Clk Source(%i)\n",
678 		setup->speed_freq, setup->clock_src);
679 	dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n",
680 		setup->rise_time, setup->fall_time);
681 	dev_dbg(i2c_dev->dev, "I2C Analog Filter(%s), DNF(%i)\n",
682 		(setup->analog_filter ? "On" : "Off"), setup->dnf);
683 
684 	i2c_dev->bus_rate = setup->speed_freq;
685 
686 	return 0;
687 }
688 
689 static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev)
690 {
691 	void __iomem *base = i2c_dev->base;
692 	u32 mask = STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN;
693 
694 	stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
695 }
696 
697 static void stm32f7_i2c_dma_callback(void *arg)
698 {
699 	struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg;
700 	struct stm32_i2c_dma *dma = i2c_dev->dma;
701 	struct device *dev = dma->chan_using->device->dev;
702 
703 	stm32f7_i2c_disable_dma_req(i2c_dev);
704 	dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir);
705 	complete(&dma->dma_complete);
706 }
707 
708 static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev)
709 {
710 	struct stm32f7_i2c_timings *t = &i2c_dev->timing;
711 	u32 timing = 0;
712 
713 	/* Timing settings */
714 	timing |= STM32F7_I2C_TIMINGR_PRESC(t->presc);
715 	timing |= STM32F7_I2C_TIMINGR_SCLDEL(t->scldel);
716 	timing |= STM32F7_I2C_TIMINGR_SDADEL(t->sdadel);
717 	timing |= STM32F7_I2C_TIMINGR_SCLH(t->sclh);
718 	timing |= STM32F7_I2C_TIMINGR_SCLL(t->scll);
719 	writel_relaxed(timing, i2c_dev->base + STM32F7_I2C_TIMINGR);
720 
721 	/* Enable I2C */
722 	if (i2c_dev->setup.analog_filter)
723 		stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
724 				     STM32F7_I2C_CR1_ANFOFF);
725 	else
726 		stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
727 				     STM32F7_I2C_CR1_ANFOFF);
728 	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
729 			     STM32F7_I2C_CR1_PE);
730 }
731 
732 static void stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev *i2c_dev)
733 {
734 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
735 	void __iomem *base = i2c_dev->base;
736 
737 	if (f7_msg->count) {
738 		writeb_relaxed(*f7_msg->buf++, base + STM32F7_I2C_TXDR);
739 		f7_msg->count--;
740 	}
741 }
742 
743 static void stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev *i2c_dev)
744 {
745 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
746 	void __iomem *base = i2c_dev->base;
747 
748 	if (f7_msg->count) {
749 		*f7_msg->buf++ = readb_relaxed(base + STM32F7_I2C_RXDR);
750 		f7_msg->count--;
751 	} else {
752 		/* Flush RX buffer has no data is expected */
753 		readb_relaxed(base + STM32F7_I2C_RXDR);
754 	}
755 }
756 
757 static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev)
758 {
759 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
760 	u32 cr2;
761 
762 	if (i2c_dev->use_dma)
763 		f7_msg->count -= STM32F7_I2C_MAX_LEN;
764 
765 	cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
766 
767 	cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK;
768 	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
769 		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
770 	} else {
771 		cr2 &= ~STM32F7_I2C_CR2_RELOAD;
772 		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
773 	}
774 
775 	writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
776 }
777 
778 static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev)
779 {
780 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
781 	u32 cr2;
782 	u8 *val;
783 
784 	/*
785 	 * For I2C_SMBUS_BLOCK_DATA && I2C_SMBUS_BLOCK_PROC_CALL, the first
786 	 * data received inform us how many data will follow.
787 	 */
788 	stm32f7_i2c_read_rx_data(i2c_dev);
789 
790 	/*
791 	 * Update NBYTES with the value read to continue the transfer
792 	 */
793 	val = f7_msg->buf - sizeof(u8);
794 	f7_msg->count = *val;
795 	cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
796 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
797 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
798 	writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
799 }
800 
801 static int stm32f7_i2c_release_bus(struct i2c_adapter *i2c_adap)
802 {
803 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
804 
805 	dev_info(i2c_dev->dev, "Trying to recover bus\n");
806 
807 	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
808 			     STM32F7_I2C_CR1_PE);
809 
810 	stm32f7_i2c_hw_config(i2c_dev);
811 
812 	return 0;
813 }
814 
815 static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev)
816 {
817 	u32 status;
818 	int ret;
819 
820 	ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F7_I2C_ISR,
821 					 status,
822 					 !(status & STM32F7_I2C_ISR_BUSY),
823 					 10, 1000);
824 	if (!ret)
825 		return 0;
826 
827 	dev_info(i2c_dev->dev, "bus busy\n");
828 
829 	ret = stm32f7_i2c_release_bus(&i2c_dev->adap);
830 	if (ret) {
831 		dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret);
832 		return ret;
833 	}
834 
835 	return -EBUSY;
836 }
837 
838 static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
839 				 struct i2c_msg *msg)
840 {
841 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
842 	void __iomem *base = i2c_dev->base;
843 	u32 cr1, cr2;
844 	int ret;
845 
846 	f7_msg->addr = msg->addr;
847 	f7_msg->buf = msg->buf;
848 	f7_msg->count = msg->len;
849 	f7_msg->result = 0;
850 	f7_msg->stop = (i2c_dev->msg_id >= i2c_dev->msg_num - 1);
851 
852 	reinit_completion(&i2c_dev->complete);
853 
854 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
855 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
856 
857 	/* Set transfer direction */
858 	cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
859 	if (msg->flags & I2C_M_RD)
860 		cr2 |= STM32F7_I2C_CR2_RD_WRN;
861 
862 	/* Set slave address */
863 	cr2 &= ~(STM32F7_I2C_CR2_HEAD10R | STM32F7_I2C_CR2_ADD10);
864 	if (msg->flags & I2C_M_TEN) {
865 		cr2 &= ~STM32F7_I2C_CR2_SADD10_MASK;
866 		cr2 |= STM32F7_I2C_CR2_SADD10(f7_msg->addr);
867 		cr2 |= STM32F7_I2C_CR2_ADD10;
868 	} else {
869 		cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
870 		cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
871 	}
872 
873 	/* Set nb bytes to transfer and reload if needed */
874 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
875 	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
876 		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
877 		cr2 |= STM32F7_I2C_CR2_RELOAD;
878 	} else {
879 		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
880 	}
881 
882 	/* Enable NACK, STOP, error and transfer complete interrupts */
883 	cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
884 		STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
885 
886 	/* Clear DMA req and TX/RX interrupt */
887 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
888 			STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
889 
890 	/* Configure DMA or enable RX/TX interrupt */
891 	i2c_dev->use_dma = false;
892 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
893 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
894 					      msg->flags & I2C_M_RD,
895 					      f7_msg->count, f7_msg->buf,
896 					      stm32f7_i2c_dma_callback,
897 					      i2c_dev);
898 		if (!ret)
899 			i2c_dev->use_dma = true;
900 		else
901 			dev_warn(i2c_dev->dev, "can't use DMA\n");
902 	}
903 
904 	if (!i2c_dev->use_dma) {
905 		if (msg->flags & I2C_M_RD)
906 			cr1 |= STM32F7_I2C_CR1_RXIE;
907 		else
908 			cr1 |= STM32F7_I2C_CR1_TXIE;
909 	} else {
910 		if (msg->flags & I2C_M_RD)
911 			cr1 |= STM32F7_I2C_CR1_RXDMAEN;
912 		else
913 			cr1 |= STM32F7_I2C_CR1_TXDMAEN;
914 	}
915 
916 	/* Configure Start/Repeated Start */
917 	cr2 |= STM32F7_I2C_CR2_START;
918 
919 	i2c_dev->master_mode = true;
920 
921 	/* Write configurations registers */
922 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
923 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
924 }
925 
926 static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
927 				      unsigned short flags, u8 command,
928 				      union i2c_smbus_data *data)
929 {
930 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
931 	struct device *dev = i2c_dev->dev;
932 	void __iomem *base = i2c_dev->base;
933 	u32 cr1, cr2;
934 	int i, ret;
935 
936 	f7_msg->result = 0;
937 	reinit_completion(&i2c_dev->complete);
938 
939 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
940 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
941 
942 	/* Set transfer direction */
943 	cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
944 	if (f7_msg->read_write)
945 		cr2 |= STM32F7_I2C_CR2_RD_WRN;
946 
947 	/* Set slave address */
948 	cr2 &= ~(STM32F7_I2C_CR2_ADD10 | STM32F7_I2C_CR2_SADD7_MASK);
949 	cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
950 
951 	f7_msg->smbus_buf[0] = command;
952 	switch (f7_msg->size) {
953 	case I2C_SMBUS_QUICK:
954 		f7_msg->stop = true;
955 		f7_msg->count = 0;
956 		break;
957 	case I2C_SMBUS_BYTE:
958 		f7_msg->stop = true;
959 		f7_msg->count = 1;
960 		break;
961 	case I2C_SMBUS_BYTE_DATA:
962 		if (f7_msg->read_write) {
963 			f7_msg->stop = false;
964 			f7_msg->count = 1;
965 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
966 		} else {
967 			f7_msg->stop = true;
968 			f7_msg->count = 2;
969 			f7_msg->smbus_buf[1] = data->byte;
970 		}
971 		break;
972 	case I2C_SMBUS_WORD_DATA:
973 		if (f7_msg->read_write) {
974 			f7_msg->stop = false;
975 			f7_msg->count = 1;
976 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
977 		} else {
978 			f7_msg->stop = true;
979 			f7_msg->count = 3;
980 			f7_msg->smbus_buf[1] = data->word & 0xff;
981 			f7_msg->smbus_buf[2] = data->word >> 8;
982 		}
983 		break;
984 	case I2C_SMBUS_BLOCK_DATA:
985 		if (f7_msg->read_write) {
986 			f7_msg->stop = false;
987 			f7_msg->count = 1;
988 			cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
989 		} else {
990 			f7_msg->stop = true;
991 			if (data->block[0] > I2C_SMBUS_BLOCK_MAX ||
992 			    !data->block[0]) {
993 				dev_err(dev, "Invalid block write size %d\n",
994 					data->block[0]);
995 				return -EINVAL;
996 			}
997 			f7_msg->count = data->block[0] + 2;
998 			for (i = 1; i < f7_msg->count; i++)
999 				f7_msg->smbus_buf[i] = data->block[i - 1];
1000 		}
1001 		break;
1002 	case I2C_SMBUS_PROC_CALL:
1003 		f7_msg->stop = false;
1004 		f7_msg->count = 3;
1005 		f7_msg->smbus_buf[1] = data->word & 0xff;
1006 		f7_msg->smbus_buf[2] = data->word >> 8;
1007 		cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
1008 		f7_msg->read_write = I2C_SMBUS_READ;
1009 		break;
1010 	case I2C_SMBUS_BLOCK_PROC_CALL:
1011 		f7_msg->stop = false;
1012 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX - 1) {
1013 			dev_err(dev, "Invalid block write size %d\n",
1014 				data->block[0]);
1015 			return -EINVAL;
1016 		}
1017 		f7_msg->count = data->block[0] + 2;
1018 		for (i = 1; i < f7_msg->count; i++)
1019 			f7_msg->smbus_buf[i] = data->block[i - 1];
1020 		cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
1021 		f7_msg->read_write = I2C_SMBUS_READ;
1022 		break;
1023 	case I2C_SMBUS_I2C_BLOCK_DATA:
1024 		/* Rely on emulated i2c transfer (through master_xfer) */
1025 		return -EOPNOTSUPP;
1026 	default:
1027 		dev_err(dev, "Unsupported smbus protocol %d\n", f7_msg->size);
1028 		return -EOPNOTSUPP;
1029 	}
1030 
1031 	f7_msg->buf = f7_msg->smbus_buf;
1032 
1033 	/* Configure PEC */
1034 	if ((flags & I2C_CLIENT_PEC) && f7_msg->size != I2C_SMBUS_QUICK) {
1035 		cr1 |= STM32F7_I2C_CR1_PECEN;
1036 		cr2 |= STM32F7_I2C_CR2_PECBYTE;
1037 		if (!f7_msg->read_write)
1038 			f7_msg->count++;
1039 	} else {
1040 		cr1 &= ~STM32F7_I2C_CR1_PECEN;
1041 		cr2 &= ~STM32F7_I2C_CR2_PECBYTE;
1042 	}
1043 
1044 	/* Set number of bytes to be transferred */
1045 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
1046 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
1047 
1048 	/* Enable NACK, STOP, error and transfer complete interrupts */
1049 	cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
1050 		STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
1051 
1052 	/* Clear DMA req and TX/RX interrupt */
1053 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
1054 			STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
1055 
1056 	/* Configure DMA or enable RX/TX interrupt */
1057 	i2c_dev->use_dma = false;
1058 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
1059 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
1060 					      cr2 & STM32F7_I2C_CR2_RD_WRN,
1061 					      f7_msg->count, f7_msg->buf,
1062 					      stm32f7_i2c_dma_callback,
1063 					      i2c_dev);
1064 		if (!ret)
1065 			i2c_dev->use_dma = true;
1066 		else
1067 			dev_warn(i2c_dev->dev, "can't use DMA\n");
1068 	}
1069 
1070 	if (!i2c_dev->use_dma) {
1071 		if (cr2 & STM32F7_I2C_CR2_RD_WRN)
1072 			cr1 |= STM32F7_I2C_CR1_RXIE;
1073 		else
1074 			cr1 |= STM32F7_I2C_CR1_TXIE;
1075 	} else {
1076 		if (cr2 & STM32F7_I2C_CR2_RD_WRN)
1077 			cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1078 		else
1079 			cr1 |= STM32F7_I2C_CR1_TXDMAEN;
1080 	}
1081 
1082 	/* Set Start bit */
1083 	cr2 |= STM32F7_I2C_CR2_START;
1084 
1085 	i2c_dev->master_mode = true;
1086 
1087 	/* Write configurations registers */
1088 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1089 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1090 
1091 	return 0;
1092 }
1093 
1094 static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev)
1095 {
1096 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1097 	void __iomem *base = i2c_dev->base;
1098 	u32 cr1, cr2;
1099 	int ret;
1100 
1101 	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
1102 	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
1103 
1104 	/* Set transfer direction */
1105 	cr2 |= STM32F7_I2C_CR2_RD_WRN;
1106 
1107 	switch (f7_msg->size) {
1108 	case I2C_SMBUS_BYTE_DATA:
1109 		f7_msg->count = 1;
1110 		break;
1111 	case I2C_SMBUS_WORD_DATA:
1112 	case I2C_SMBUS_PROC_CALL:
1113 		f7_msg->count = 2;
1114 		break;
1115 	case I2C_SMBUS_BLOCK_DATA:
1116 	case I2C_SMBUS_BLOCK_PROC_CALL:
1117 		f7_msg->count = 1;
1118 		cr2 |= STM32F7_I2C_CR2_RELOAD;
1119 		break;
1120 	}
1121 
1122 	f7_msg->buf = f7_msg->smbus_buf;
1123 	f7_msg->stop = true;
1124 
1125 	/* Add one byte for PEC if needed */
1126 	if (cr1 & STM32F7_I2C_CR1_PECEN)
1127 		f7_msg->count++;
1128 
1129 	/* Set number of bytes to be transferred */
1130 	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK);
1131 	cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
1132 
1133 	/*
1134 	 * Configure RX/TX interrupt:
1135 	 */
1136 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE);
1137 	cr1 |= STM32F7_I2C_CR1_RXIE;
1138 
1139 	/*
1140 	 * Configure DMA or enable RX/TX interrupt:
1141 	 * For I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_BLOCK_PROC_CALL we don't use
1142 	 * dma as we don't know in advance how many data will be received
1143 	 */
1144 	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
1145 		 STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
1146 
1147 	i2c_dev->use_dma = false;
1148 	if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN &&
1149 	    f7_msg->size != I2C_SMBUS_BLOCK_DATA &&
1150 	    f7_msg->size != I2C_SMBUS_BLOCK_PROC_CALL) {
1151 		ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
1152 					      cr2 & STM32F7_I2C_CR2_RD_WRN,
1153 					      f7_msg->count, f7_msg->buf,
1154 					      stm32f7_i2c_dma_callback,
1155 					      i2c_dev);
1156 
1157 		if (!ret)
1158 			i2c_dev->use_dma = true;
1159 		else
1160 			dev_warn(i2c_dev->dev, "can't use DMA\n");
1161 	}
1162 
1163 	if (!i2c_dev->use_dma)
1164 		cr1 |= STM32F7_I2C_CR1_RXIE;
1165 	else
1166 		cr1 |= STM32F7_I2C_CR1_RXDMAEN;
1167 
1168 	/* Configure Repeated Start */
1169 	cr2 |= STM32F7_I2C_CR2_START;
1170 
1171 	/* Write configurations registers */
1172 	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
1173 	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
1174 }
1175 
1176 static int stm32f7_i2c_smbus_check_pec(struct stm32f7_i2c_dev *i2c_dev)
1177 {
1178 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1179 	u8 count, internal_pec, received_pec;
1180 
1181 	internal_pec = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
1182 
1183 	switch (f7_msg->size) {
1184 	case I2C_SMBUS_BYTE:
1185 	case I2C_SMBUS_BYTE_DATA:
1186 		received_pec = f7_msg->smbus_buf[1];
1187 		break;
1188 	case I2C_SMBUS_WORD_DATA:
1189 	case I2C_SMBUS_PROC_CALL:
1190 		received_pec = f7_msg->smbus_buf[2];
1191 		break;
1192 	case I2C_SMBUS_BLOCK_DATA:
1193 	case I2C_SMBUS_BLOCK_PROC_CALL:
1194 		count = f7_msg->smbus_buf[0];
1195 		received_pec = f7_msg->smbus_buf[count];
1196 		break;
1197 	default:
1198 		dev_err(i2c_dev->dev, "Unsupported smbus protocol for PEC\n");
1199 		return -EINVAL;
1200 	}
1201 
1202 	if (internal_pec != received_pec) {
1203 		dev_err(i2c_dev->dev, "Bad PEC 0x%02x vs. 0x%02x\n",
1204 			internal_pec, received_pec);
1205 		return -EBADMSG;
1206 	}
1207 
1208 	return 0;
1209 }
1210 
1211 static bool stm32f7_i2c_is_addr_match(struct i2c_client *slave, u32 addcode)
1212 {
1213 	u32 addr;
1214 
1215 	if (!slave)
1216 		return false;
1217 
1218 	if (slave->flags & I2C_CLIENT_TEN) {
1219 		/*
1220 		 * For 10-bit addr, addcode = 11110XY with
1221 		 * X = Bit 9 of slave address
1222 		 * Y = Bit 8 of slave address
1223 		 */
1224 		addr = slave->addr >> 8;
1225 		addr |= 0x78;
1226 		if (addr == addcode)
1227 			return true;
1228 	} else {
1229 		addr = slave->addr & 0x7f;
1230 		if (addr == addcode)
1231 			return true;
1232 	}
1233 
1234 	return false;
1235 }
1236 
1237 static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
1238 {
1239 	struct i2c_client *slave = i2c_dev->slave_running;
1240 	void __iomem *base = i2c_dev->base;
1241 	u32 mask;
1242 	u8 value = 0;
1243 
1244 	if (i2c_dev->slave_dir) {
1245 		/* Notify i2c slave that new read transfer is starting */
1246 		i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
1247 
1248 		/*
1249 		 * Disable slave TX config in case of I2C combined message
1250 		 * (I2C Write followed by I2C Read)
1251 		 */
1252 		mask = STM32F7_I2C_CR2_RELOAD;
1253 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, mask);
1254 		mask = STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1255 		       STM32F7_I2C_CR1_TCIE;
1256 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
1257 
1258 		/* Enable TX empty, STOP, NACK interrupts */
1259 		mask =  STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1260 			STM32F7_I2C_CR1_TXIE;
1261 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1262 
1263 		/* Write 1st data byte */
1264 		writel_relaxed(value, base + STM32F7_I2C_TXDR);
1265 	} else {
1266 		/* Notify i2c slave that new write transfer is starting */
1267 		i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
1268 
1269 		/* Set reload mode to be able to ACK/NACK each received byte */
1270 		mask = STM32F7_I2C_CR2_RELOAD;
1271 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1272 
1273 		/*
1274 		 * Set STOP, NACK, RX empty and transfer complete interrupts.*
1275 		 * Set Slave Byte Control to be able to ACK/NACK each data
1276 		 * byte received
1277 		 */
1278 		mask =  STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
1279 			STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
1280 			STM32F7_I2C_CR1_TCIE;
1281 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1282 	}
1283 }
1284 
1285 static void stm32f7_i2c_slave_addr(struct stm32f7_i2c_dev *i2c_dev)
1286 {
1287 	void __iomem *base = i2c_dev->base;
1288 	u32 isr, addcode, dir, mask;
1289 	int i;
1290 
1291 	isr = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1292 	addcode = STM32F7_I2C_ISR_ADDCODE_GET(isr);
1293 	dir = isr & STM32F7_I2C_ISR_DIR;
1294 
1295 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1296 		if (stm32f7_i2c_is_addr_match(i2c_dev->slave[i], addcode)) {
1297 			i2c_dev->slave_running = i2c_dev->slave[i];
1298 			i2c_dev->slave_dir = dir;
1299 
1300 			/* Start I2C slave processing */
1301 			stm32f7_i2c_slave_start(i2c_dev);
1302 
1303 			/* Clear ADDR flag */
1304 			mask = STM32F7_I2C_ICR_ADDRCF;
1305 			writel_relaxed(mask, base + STM32F7_I2C_ICR);
1306 			break;
1307 		}
1308 	}
1309 }
1310 
1311 static int stm32f7_i2c_get_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1312 				    struct i2c_client *slave, int *id)
1313 {
1314 	int i;
1315 
1316 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1317 		if (i2c_dev->slave[i] == slave) {
1318 			*id = i;
1319 			return 0;
1320 		}
1321 	}
1322 
1323 	dev_err(i2c_dev->dev, "Slave 0x%x not registered\n", slave->addr);
1324 
1325 	return -ENODEV;
1326 }
1327 
1328 static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
1329 					 struct i2c_client *slave, int *id)
1330 {
1331 	struct device *dev = i2c_dev->dev;
1332 	int i;
1333 
1334 	/*
1335 	 * slave[STM32F7_SLAVE_HOSTNOTIFY] support only SMBus Host address (0x8)
1336 	 * slave[STM32F7_SLAVE_7_10_BITS_ADDR] supports 7-bit and 10-bit slave address
1337 	 * slave[STM32F7_SLAVE_7_BITS_ADDR] supports 7-bit slave address only
1338 	 */
1339 	if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
1340 		if (i2c_dev->slave[STM32F7_SLAVE_HOSTNOTIFY])
1341 			goto fail;
1342 		*id = STM32F7_SLAVE_HOSTNOTIFY;
1343 		return 0;
1344 	}
1345 
1346 	for (i = STM32F7_I2C_MAX_SLAVE - 1; i > STM32F7_SLAVE_HOSTNOTIFY; i--) {
1347 		if ((i == STM32F7_SLAVE_7_BITS_ADDR) &&
1348 		    (slave->flags & I2C_CLIENT_TEN))
1349 			continue;
1350 		if (!i2c_dev->slave[i]) {
1351 			*id = i;
1352 			return 0;
1353 		}
1354 	}
1355 
1356 fail:
1357 	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
1358 
1359 	return -EINVAL;
1360 }
1361 
1362 static bool stm32f7_i2c_is_slave_registered(struct stm32f7_i2c_dev *i2c_dev)
1363 {
1364 	int i;
1365 
1366 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1367 		if (i2c_dev->slave[i])
1368 			return true;
1369 	}
1370 
1371 	return false;
1372 }
1373 
1374 static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev)
1375 {
1376 	int i, busy;
1377 
1378 	busy = 0;
1379 	for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
1380 		if (i2c_dev->slave[i])
1381 			busy++;
1382 	}
1383 
1384 	return i == busy;
1385 }
1386 
1387 static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev)
1388 {
1389 	void __iomem *base = i2c_dev->base;
1390 	u32 cr2, status, mask;
1391 	u8 val;
1392 	int ret;
1393 
1394 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1395 
1396 	/* Slave transmitter mode */
1397 	if (status & STM32F7_I2C_ISR_TXIS) {
1398 		i2c_slave_event(i2c_dev->slave_running,
1399 				I2C_SLAVE_READ_PROCESSED,
1400 				&val);
1401 
1402 		/* Write data byte */
1403 		writel_relaxed(val, base + STM32F7_I2C_TXDR);
1404 	}
1405 
1406 	/* Transfer Complete Reload for Slave receiver mode */
1407 	if (status & STM32F7_I2C_ISR_TCR || status & STM32F7_I2C_ISR_RXNE) {
1408 		/*
1409 		 * Read data byte then set NBYTES to receive next byte or NACK
1410 		 * the current received byte
1411 		 */
1412 		val = readb_relaxed(i2c_dev->base + STM32F7_I2C_RXDR);
1413 		ret = i2c_slave_event(i2c_dev->slave_running,
1414 				      I2C_SLAVE_WRITE_RECEIVED,
1415 				      &val);
1416 		if (!ret) {
1417 			cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
1418 			cr2 |= STM32F7_I2C_CR2_NBYTES(1);
1419 			writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
1420 		} else {
1421 			mask = STM32F7_I2C_CR2_NACK;
1422 			stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1423 		}
1424 	}
1425 
1426 	/* NACK received */
1427 	if (status & STM32F7_I2C_ISR_NACKF) {
1428 		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__);
1429 		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1430 	}
1431 
1432 	/* STOP received */
1433 	if (status & STM32F7_I2C_ISR_STOPF) {
1434 		/* Disable interrupts */
1435 		stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_XFER_IRQ_MASK);
1436 
1437 		if (i2c_dev->slave_dir) {
1438 			/*
1439 			 * Flush TX buffer in order to not used the byte in
1440 			 * TXDR for the next transfer
1441 			 */
1442 			mask = STM32F7_I2C_ISR_TXE;
1443 			stm32f7_i2c_set_bits(base + STM32F7_I2C_ISR, mask);
1444 		}
1445 
1446 		/* Clear STOP flag */
1447 		writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1448 
1449 		/* Notify i2c slave that a STOP flag has been detected */
1450 		i2c_slave_event(i2c_dev->slave_running, I2C_SLAVE_STOP, &val);
1451 
1452 		i2c_dev->slave_running = NULL;
1453 	}
1454 
1455 	/* Address match received */
1456 	if (status & STM32F7_I2C_ISR_ADDR)
1457 		stm32f7_i2c_slave_addr(i2c_dev);
1458 
1459 	return IRQ_HANDLED;
1460 }
1461 
1462 static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
1463 {
1464 	struct stm32f7_i2c_dev *i2c_dev = data;
1465 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1466 	void __iomem *base = i2c_dev->base;
1467 	u32 status, mask;
1468 	int ret = IRQ_HANDLED;
1469 
1470 	/* Check if the interrupt if for a slave device */
1471 	if (!i2c_dev->master_mode) {
1472 		ret = stm32f7_i2c_slave_isr_event(i2c_dev);
1473 		return ret;
1474 	}
1475 
1476 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1477 
1478 	/* Tx empty */
1479 	if (status & STM32F7_I2C_ISR_TXIS)
1480 		stm32f7_i2c_write_tx_data(i2c_dev);
1481 
1482 	/* RX not empty */
1483 	if (status & STM32F7_I2C_ISR_RXNE)
1484 		stm32f7_i2c_read_rx_data(i2c_dev);
1485 
1486 	/* NACK received */
1487 	if (status & STM32F7_I2C_ISR_NACKF) {
1488 		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",
1489 			__func__, f7_msg->addr);
1490 		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
1491 		f7_msg->result = -ENXIO;
1492 	}
1493 
1494 	/* STOP detection flag */
1495 	if (status & STM32F7_I2C_ISR_STOPF) {
1496 		/* Disable interrupts */
1497 		if (stm32f7_i2c_is_slave_registered(i2c_dev))
1498 			mask = STM32F7_I2C_XFER_IRQ_MASK;
1499 		else
1500 			mask = STM32F7_I2C_ALL_IRQ_MASK;
1501 		stm32f7_i2c_disable_irq(i2c_dev, mask);
1502 
1503 		/* Clear STOP flag */
1504 		writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
1505 
1506 		if (i2c_dev->use_dma) {
1507 			ret = IRQ_WAKE_THREAD;
1508 		} else {
1509 			i2c_dev->master_mode = false;
1510 			complete(&i2c_dev->complete);
1511 		}
1512 	}
1513 
1514 	/* Transfer complete */
1515 	if (status & STM32F7_I2C_ISR_TC) {
1516 		if (f7_msg->stop) {
1517 			mask = STM32F7_I2C_CR2_STOP;
1518 			stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
1519 		} else if (i2c_dev->use_dma) {
1520 			ret = IRQ_WAKE_THREAD;
1521 		} else if (f7_msg->smbus) {
1522 			stm32f7_i2c_smbus_rep_start(i2c_dev);
1523 		} else {
1524 			i2c_dev->msg_id++;
1525 			i2c_dev->msg++;
1526 			stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1527 		}
1528 	}
1529 
1530 	if (status & STM32F7_I2C_ISR_TCR) {
1531 		if (f7_msg->smbus)
1532 			stm32f7_i2c_smbus_reload(i2c_dev);
1533 		else
1534 			stm32f7_i2c_reload(i2c_dev);
1535 	}
1536 
1537 	return ret;
1538 }
1539 
1540 static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
1541 {
1542 	struct stm32f7_i2c_dev *i2c_dev = data;
1543 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1544 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1545 	u32 status;
1546 	int ret;
1547 
1548 	/*
1549 	 * Wait for dma transfer completion before sending next message or
1550 	 * notity the end of xfer to the client
1551 	 */
1552 	ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ);
1553 	if (!ret) {
1554 		dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
1555 		stm32f7_i2c_disable_dma_req(i2c_dev);
1556 		dmaengine_terminate_all(dma->chan_using);
1557 		f7_msg->result = -ETIMEDOUT;
1558 	}
1559 
1560 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1561 
1562 	if (status & STM32F7_I2C_ISR_TC) {
1563 		if (f7_msg->smbus) {
1564 			stm32f7_i2c_smbus_rep_start(i2c_dev);
1565 		} else {
1566 			i2c_dev->msg_id++;
1567 			i2c_dev->msg++;
1568 			stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
1569 		}
1570 	} else {
1571 		i2c_dev->master_mode = false;
1572 		complete(&i2c_dev->complete);
1573 	}
1574 
1575 	return IRQ_HANDLED;
1576 }
1577 
1578 static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
1579 {
1580 	struct stm32f7_i2c_dev *i2c_dev = data;
1581 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1582 	void __iomem *base = i2c_dev->base;
1583 	struct device *dev = i2c_dev->dev;
1584 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1585 	u32 status;
1586 
1587 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
1588 
1589 	/* Bus error */
1590 	if (status & STM32F7_I2C_ISR_BERR) {
1591 		dev_err(dev, "<%s>: Bus error\n", __func__);
1592 		writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR);
1593 		stm32f7_i2c_release_bus(&i2c_dev->adap);
1594 		f7_msg->result = -EIO;
1595 	}
1596 
1597 	/* Arbitration loss */
1598 	if (status & STM32F7_I2C_ISR_ARLO) {
1599 		dev_dbg(dev, "<%s>: Arbitration loss\n", __func__);
1600 		writel_relaxed(STM32F7_I2C_ICR_ARLOCF, base + STM32F7_I2C_ICR);
1601 		f7_msg->result = -EAGAIN;
1602 	}
1603 
1604 	if (status & STM32F7_I2C_ISR_PECERR) {
1605 		dev_err(dev, "<%s>: PEC error in reception\n", __func__);
1606 		writel_relaxed(STM32F7_I2C_ICR_PECCF, base + STM32F7_I2C_ICR);
1607 		f7_msg->result = -EINVAL;
1608 	}
1609 
1610 	if (!i2c_dev->slave_running) {
1611 		u32 mask;
1612 		/* Disable interrupts */
1613 		if (stm32f7_i2c_is_slave_registered(i2c_dev))
1614 			mask = STM32F7_I2C_XFER_IRQ_MASK;
1615 		else
1616 			mask = STM32F7_I2C_ALL_IRQ_MASK;
1617 		stm32f7_i2c_disable_irq(i2c_dev, mask);
1618 	}
1619 
1620 	/* Disable dma */
1621 	if (i2c_dev->use_dma) {
1622 		stm32f7_i2c_disable_dma_req(i2c_dev);
1623 		dmaengine_terminate_all(dma->chan_using);
1624 	}
1625 
1626 	i2c_dev->master_mode = false;
1627 	complete(&i2c_dev->complete);
1628 
1629 	return IRQ_HANDLED;
1630 }
1631 
1632 static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
1633 			    struct i2c_msg msgs[], int num)
1634 {
1635 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
1636 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1637 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1638 	unsigned long time_left;
1639 	int ret;
1640 
1641 	i2c_dev->msg = msgs;
1642 	i2c_dev->msg_num = num;
1643 	i2c_dev->msg_id = 0;
1644 	f7_msg->smbus = false;
1645 
1646 	ret = pm_runtime_get_sync(i2c_dev->dev);
1647 	if (ret < 0)
1648 		return ret;
1649 
1650 	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1651 	if (ret)
1652 		goto pm_free;
1653 
1654 	stm32f7_i2c_xfer_msg(i2c_dev, msgs);
1655 
1656 	time_left = wait_for_completion_timeout(&i2c_dev->complete,
1657 						i2c_dev->adap.timeout);
1658 	ret = f7_msg->result;
1659 
1660 	if (!time_left) {
1661 		dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n",
1662 			i2c_dev->msg->addr);
1663 		if (i2c_dev->use_dma)
1664 			dmaengine_terminate_all(dma->chan_using);
1665 		ret = -ETIMEDOUT;
1666 	}
1667 
1668 pm_free:
1669 	pm_runtime_mark_last_busy(i2c_dev->dev);
1670 	pm_runtime_put_autosuspend(i2c_dev->dev);
1671 
1672 	return (ret < 0) ? ret : num;
1673 }
1674 
1675 static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
1676 				  unsigned short flags, char read_write,
1677 				  u8 command, int size,
1678 				  union i2c_smbus_data *data)
1679 {
1680 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adapter);
1681 	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
1682 	struct stm32_i2c_dma *dma = i2c_dev->dma;
1683 	struct device *dev = i2c_dev->dev;
1684 	unsigned long timeout;
1685 	int i, ret;
1686 
1687 	f7_msg->addr = addr;
1688 	f7_msg->size = size;
1689 	f7_msg->read_write = read_write;
1690 	f7_msg->smbus = true;
1691 
1692 	ret = pm_runtime_get_sync(dev);
1693 	if (ret < 0)
1694 		return ret;
1695 
1696 	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
1697 	if (ret)
1698 		goto pm_free;
1699 
1700 	ret = stm32f7_i2c_smbus_xfer_msg(i2c_dev, flags, command, data);
1701 	if (ret)
1702 		goto pm_free;
1703 
1704 	timeout = wait_for_completion_timeout(&i2c_dev->complete,
1705 					      i2c_dev->adap.timeout);
1706 	ret = f7_msg->result;
1707 	if (ret)
1708 		goto pm_free;
1709 
1710 	if (!timeout) {
1711 		dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr);
1712 		if (i2c_dev->use_dma)
1713 			dmaengine_terminate_all(dma->chan_using);
1714 		ret = -ETIMEDOUT;
1715 		goto pm_free;
1716 	}
1717 
1718 	/* Check PEC */
1719 	if ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && read_write) {
1720 		ret = stm32f7_i2c_smbus_check_pec(i2c_dev);
1721 		if (ret)
1722 			goto pm_free;
1723 	}
1724 
1725 	if (read_write && size != I2C_SMBUS_QUICK) {
1726 		switch (size) {
1727 		case I2C_SMBUS_BYTE:
1728 		case I2C_SMBUS_BYTE_DATA:
1729 			data->byte = f7_msg->smbus_buf[0];
1730 		break;
1731 		case I2C_SMBUS_WORD_DATA:
1732 		case I2C_SMBUS_PROC_CALL:
1733 			data->word = f7_msg->smbus_buf[0] |
1734 				(f7_msg->smbus_buf[1] << 8);
1735 		break;
1736 		case I2C_SMBUS_BLOCK_DATA:
1737 		case I2C_SMBUS_BLOCK_PROC_CALL:
1738 		for (i = 0; i <= f7_msg->smbus_buf[0]; i++)
1739 			data->block[i] = f7_msg->smbus_buf[i];
1740 		break;
1741 		default:
1742 			dev_err(dev, "Unsupported smbus transaction\n");
1743 			ret = -EINVAL;
1744 		}
1745 	}
1746 
1747 pm_free:
1748 	pm_runtime_mark_last_busy(dev);
1749 	pm_runtime_put_autosuspend(dev);
1750 	return ret;
1751 }
1752 
1753 static void stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev *i2c_dev,
1754 				      bool enable)
1755 {
1756 	void __iomem *base = i2c_dev->base;
1757 	u32 mask = STM32F7_I2C_CR1_WUPEN;
1758 
1759 	if (!i2c_dev->wakeup_src)
1760 		return;
1761 
1762 	if (enable) {
1763 		device_set_wakeup_enable(i2c_dev->dev, true);
1764 		stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1765 	} else {
1766 		device_set_wakeup_enable(i2c_dev->dev, false);
1767 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
1768 	}
1769 }
1770 
1771 static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
1772 {
1773 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1774 	void __iomem *base = i2c_dev->base;
1775 	struct device *dev = i2c_dev->dev;
1776 	u32 oar1, oar2, mask;
1777 	int id, ret;
1778 
1779 	if (slave->flags & I2C_CLIENT_PEC) {
1780 		dev_err(dev, "SMBus PEC not supported in slave mode\n");
1781 		return -EINVAL;
1782 	}
1783 
1784 	if (stm32f7_i2c_is_slave_busy(i2c_dev)) {
1785 		dev_err(dev, "Too much slave registered\n");
1786 		return -EBUSY;
1787 	}
1788 
1789 	ret = stm32f7_i2c_get_free_slave_id(i2c_dev, slave, &id);
1790 	if (ret)
1791 		return ret;
1792 
1793 	ret = pm_runtime_get_sync(dev);
1794 	if (ret < 0)
1795 		return ret;
1796 
1797 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
1798 		stm32f7_i2c_enable_wakeup(i2c_dev, true);
1799 
1800 	switch (id) {
1801 	case 0:
1802 		/* Slave SMBus Host */
1803 		i2c_dev->slave[id] = slave;
1804 		break;
1805 
1806 	case 1:
1807 		/* Configure Own Address 1 */
1808 		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
1809 		oar1 &= ~STM32F7_I2C_OAR1_MASK;
1810 		if (slave->flags & I2C_CLIENT_TEN) {
1811 			oar1 |= STM32F7_I2C_OAR1_OA1_10(slave->addr);
1812 			oar1 |= STM32F7_I2C_OAR1_OA1MODE;
1813 		} else {
1814 			oar1 |= STM32F7_I2C_OAR1_OA1_7(slave->addr);
1815 		}
1816 		oar1 |= STM32F7_I2C_OAR1_OA1EN;
1817 		i2c_dev->slave[id] = slave;
1818 		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
1819 		break;
1820 
1821 	case 2:
1822 		/* Configure Own Address 2 */
1823 		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
1824 		oar2 &= ~STM32F7_I2C_OAR2_MASK;
1825 		if (slave->flags & I2C_CLIENT_TEN) {
1826 			ret = -EOPNOTSUPP;
1827 			goto pm_free;
1828 		}
1829 
1830 		oar2 |= STM32F7_I2C_OAR2_OA2_7(slave->addr);
1831 		oar2 |= STM32F7_I2C_OAR2_OA2EN;
1832 		i2c_dev->slave[id] = slave;
1833 		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
1834 		break;
1835 
1836 	default:
1837 		dev_err(dev, "I2C slave id not supported\n");
1838 		ret = -ENODEV;
1839 		goto pm_free;
1840 	}
1841 
1842 	/* Enable ACK */
1843 	stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, STM32F7_I2C_CR2_NACK);
1844 
1845 	/* Enable Address match interrupt, error interrupt and enable I2C  */
1846 	mask = STM32F7_I2C_CR1_ADDRIE | STM32F7_I2C_CR1_ERRIE |
1847 		STM32F7_I2C_CR1_PE;
1848 	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
1849 
1850 	ret = 0;
1851 pm_free:
1852 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
1853 		stm32f7_i2c_enable_wakeup(i2c_dev, false);
1854 
1855 	pm_runtime_mark_last_busy(dev);
1856 	pm_runtime_put_autosuspend(dev);
1857 
1858 	return ret;
1859 }
1860 
1861 static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
1862 {
1863 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
1864 	void __iomem *base = i2c_dev->base;
1865 	u32 mask;
1866 	int id, ret;
1867 
1868 	ret = stm32f7_i2c_get_slave_id(i2c_dev, slave, &id);
1869 	if (ret)
1870 		return ret;
1871 
1872 	WARN_ON(!i2c_dev->slave[id]);
1873 
1874 	ret = pm_runtime_get_sync(i2c_dev->dev);
1875 	if (ret < 0)
1876 		return ret;
1877 
1878 	if (id == 1) {
1879 		mask = STM32F7_I2C_OAR1_OA1EN;
1880 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
1881 	} else if (id == 2) {
1882 		mask = STM32F7_I2C_OAR2_OA2EN;
1883 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
1884 	}
1885 
1886 	i2c_dev->slave[id] = NULL;
1887 
1888 	if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
1889 		stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
1890 		stm32f7_i2c_enable_wakeup(i2c_dev, false);
1891 	}
1892 
1893 	pm_runtime_mark_last_busy(i2c_dev->dev);
1894 	pm_runtime_put_autosuspend(i2c_dev->dev);
1895 
1896 	return 0;
1897 }
1898 
1899 static int stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev *i2c_dev,
1900 					  bool enable)
1901 {
1902 	int ret;
1903 
1904 	if (i2c_dev->bus_rate <= I2C_MAX_FAST_MODE_FREQ ||
1905 	    IS_ERR_OR_NULL(i2c_dev->regmap))
1906 		/* Optional */
1907 		return 0;
1908 
1909 	if (i2c_dev->fmp_sreg == i2c_dev->fmp_creg)
1910 		ret = regmap_update_bits(i2c_dev->regmap,
1911 					 i2c_dev->fmp_sreg,
1912 					 i2c_dev->fmp_mask,
1913 					 enable ? i2c_dev->fmp_mask : 0);
1914 	else
1915 		ret = regmap_write(i2c_dev->regmap,
1916 				   enable ? i2c_dev->fmp_sreg :
1917 					    i2c_dev->fmp_creg,
1918 				   i2c_dev->fmp_mask);
1919 
1920 	return ret;
1921 }
1922 
1923 static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
1924 					  struct stm32f7_i2c_dev *i2c_dev)
1925 {
1926 	struct device_node *np = pdev->dev.of_node;
1927 	int ret;
1928 
1929 	i2c_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg-fmp");
1930 	if (IS_ERR(i2c_dev->regmap))
1931 		/* Optional */
1932 		return 0;
1933 
1934 	ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1,
1935 					 &i2c_dev->fmp_sreg);
1936 	if (ret)
1937 		return ret;
1938 
1939 	i2c_dev->fmp_creg = i2c_dev->fmp_sreg +
1940 			       i2c_dev->setup.fmp_clr_offset;
1941 
1942 	return of_property_read_u32_index(np, "st,syscfg-fmp", 2,
1943 					  &i2c_dev->fmp_mask);
1944 }
1945 
1946 static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
1947 {
1948 	struct i2c_adapter *adap = &i2c_dev->adap;
1949 	void __iomem *base = i2c_dev->base;
1950 	struct i2c_client *client;
1951 
1952 	client = i2c_new_slave_host_notify_device(adap);
1953 	if (IS_ERR(client))
1954 		return PTR_ERR(client);
1955 
1956 	i2c_dev->host_notify_client = client;
1957 
1958 	/* Enable SMBus Host address */
1959 	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
1960 
1961 	return 0;
1962 }
1963 
1964 static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
1965 {
1966 	void __iomem *base = i2c_dev->base;
1967 
1968 	if (i2c_dev->host_notify_client) {
1969 		/* Disable SMBus Host address */
1970 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
1971 				     STM32F7_I2C_CR1_SMBHEN);
1972 		i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
1973 	}
1974 }
1975 
1976 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
1977 {
1978 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1979 
1980 	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
1981 		   I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
1982 		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
1983 		   I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
1984 		   I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
1985 		   I2C_FUNC_SMBUS_I2C_BLOCK;
1986 
1987 	if (i2c_dev->smbus_mode)
1988 		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
1989 
1990 	return func;
1991 }
1992 
1993 static const struct i2c_algorithm stm32f7_i2c_algo = {
1994 	.master_xfer = stm32f7_i2c_xfer,
1995 	.smbus_xfer = stm32f7_i2c_smbus_xfer,
1996 	.functionality = stm32f7_i2c_func,
1997 	.reg_slave = stm32f7_i2c_reg_slave,
1998 	.unreg_slave = stm32f7_i2c_unreg_slave,
1999 };
2000 
2001 static int stm32f7_i2c_probe(struct platform_device *pdev)
2002 {
2003 	struct stm32f7_i2c_dev *i2c_dev;
2004 	const struct stm32f7_i2c_setup *setup;
2005 	struct resource *res;
2006 	struct i2c_adapter *adap;
2007 	struct reset_control *rst;
2008 	dma_addr_t phy_addr;
2009 	int irq_error, irq_event, ret;
2010 
2011 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
2012 	if (!i2c_dev)
2013 		return -ENOMEM;
2014 
2015 	i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2016 	if (IS_ERR(i2c_dev->base))
2017 		return PTR_ERR(i2c_dev->base);
2018 	phy_addr = (dma_addr_t)res->start;
2019 
2020 	irq_event = platform_get_irq(pdev, 0);
2021 	if (irq_event <= 0) {
2022 		if (irq_event != -EPROBE_DEFER)
2023 			dev_err(&pdev->dev, "Failed to get IRQ event: %d\n",
2024 				irq_event);
2025 		return irq_event ? : -ENOENT;
2026 	}
2027 
2028 	irq_error = platform_get_irq(pdev, 1);
2029 	if (irq_error <= 0) {
2030 		if (irq_error != -EPROBE_DEFER)
2031 			dev_err(&pdev->dev, "Failed to get IRQ error: %d\n",
2032 				irq_error);
2033 		return irq_error ? : -ENOENT;
2034 	}
2035 
2036 	i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node,
2037 						    "wakeup-source");
2038 
2039 	i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
2040 	if (IS_ERR(i2c_dev->clk))
2041 		return dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->clk),
2042 				     "Failed to get controller clock\n");
2043 
2044 	ret = clk_prepare_enable(i2c_dev->clk);
2045 	if (ret) {
2046 		dev_err(&pdev->dev, "Failed to prepare_enable clock\n");
2047 		return ret;
2048 	}
2049 
2050 	rst = devm_reset_control_get(&pdev->dev, NULL);
2051 	if (IS_ERR(rst)) {
2052 		ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
2053 				    "Error: Missing reset ctrl\n");
2054 		goto clk_free;
2055 	}
2056 	reset_control_assert(rst);
2057 	udelay(2);
2058 	reset_control_deassert(rst);
2059 
2060 	i2c_dev->dev = &pdev->dev;
2061 
2062 	ret = devm_request_threaded_irq(&pdev->dev, irq_event,
2063 					stm32f7_i2c_isr_event,
2064 					stm32f7_i2c_isr_event_thread,
2065 					IRQF_ONESHOT,
2066 					pdev->name, i2c_dev);
2067 	if (ret) {
2068 		dev_err(&pdev->dev, "Failed to request irq event %i\n",
2069 			irq_event);
2070 		goto clk_free;
2071 	}
2072 
2073 	ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0,
2074 			       pdev->name, i2c_dev);
2075 	if (ret) {
2076 		dev_err(&pdev->dev, "Failed to request irq error %i\n",
2077 			irq_error);
2078 		goto clk_free;
2079 	}
2080 
2081 	setup = of_device_get_match_data(&pdev->dev);
2082 	if (!setup) {
2083 		dev_err(&pdev->dev, "Can't get device data\n");
2084 		ret = -ENODEV;
2085 		goto clk_free;
2086 	}
2087 	i2c_dev->setup = *setup;
2088 
2089 	ret = stm32f7_i2c_setup_timing(i2c_dev, &i2c_dev->setup);
2090 	if (ret)
2091 		goto clk_free;
2092 
2093 	/* Setup Fast mode plus if necessary */
2094 	if (i2c_dev->bus_rate > I2C_MAX_FAST_MODE_FREQ) {
2095 		ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
2096 		if (ret)
2097 			goto clk_free;
2098 		ret = stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
2099 		if (ret)
2100 			goto clk_free;
2101 	}
2102 
2103 	adap = &i2c_dev->adap;
2104 	i2c_set_adapdata(adap, i2c_dev);
2105 	snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
2106 		 &res->start);
2107 	adap->owner = THIS_MODULE;
2108 	adap->timeout = 2 * HZ;
2109 	adap->retries = 3;
2110 	adap->algo = &stm32f7_i2c_algo;
2111 	adap->dev.parent = &pdev->dev;
2112 	adap->dev.of_node = pdev->dev.of_node;
2113 
2114 	init_completion(&i2c_dev->complete);
2115 
2116 	/* Init DMA config if supported */
2117 	i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
2118 					     STM32F7_I2C_TXDR,
2119 					     STM32F7_I2C_RXDR);
2120 	if (IS_ERR(i2c_dev->dma)) {
2121 		ret = PTR_ERR(i2c_dev->dma);
2122 		/* DMA support is optional, only report other errors */
2123 		if (ret != -ENODEV)
2124 			goto fmp_clear;
2125 		dev_dbg(i2c_dev->dev, "No DMA option: fallback using interrupts\n");
2126 		i2c_dev->dma = NULL;
2127 	}
2128 
2129 	if (i2c_dev->wakeup_src) {
2130 		device_set_wakeup_capable(i2c_dev->dev, true);
2131 
2132 		ret = dev_pm_set_wake_irq(i2c_dev->dev, irq_event);
2133 		if (ret) {
2134 			dev_err(i2c_dev->dev, "Failed to set wake up irq\n");
2135 			goto clr_wakeup_capable;
2136 		}
2137 	}
2138 
2139 	platform_set_drvdata(pdev, i2c_dev);
2140 
2141 	pm_runtime_set_autosuspend_delay(i2c_dev->dev,
2142 					 STM32F7_AUTOSUSPEND_DELAY);
2143 	pm_runtime_use_autosuspend(i2c_dev->dev);
2144 	pm_runtime_set_active(i2c_dev->dev);
2145 	pm_runtime_enable(i2c_dev->dev);
2146 
2147 	pm_runtime_get_noresume(&pdev->dev);
2148 
2149 	stm32f7_i2c_hw_config(i2c_dev);
2150 
2151 	i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
2152 
2153 	ret = i2c_add_adapter(adap);
2154 	if (ret)
2155 		goto pm_disable;
2156 
2157 	if (i2c_dev->smbus_mode) {
2158 		ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
2159 		if (ret) {
2160 			dev_err(i2c_dev->dev,
2161 				"failed to enable SMBus Host-Notify protocol (%d)\n",
2162 				ret);
2163 			goto i2c_adapter_remove;
2164 		}
2165 	}
2166 
2167 	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
2168 
2169 	pm_runtime_mark_last_busy(i2c_dev->dev);
2170 	pm_runtime_put_autosuspend(i2c_dev->dev);
2171 
2172 	return 0;
2173 
2174 i2c_adapter_remove:
2175 	i2c_del_adapter(adap);
2176 
2177 pm_disable:
2178 	pm_runtime_put_noidle(i2c_dev->dev);
2179 	pm_runtime_disable(i2c_dev->dev);
2180 	pm_runtime_set_suspended(i2c_dev->dev);
2181 	pm_runtime_dont_use_autosuspend(i2c_dev->dev);
2182 
2183 	if (i2c_dev->wakeup_src)
2184 		dev_pm_clear_wake_irq(i2c_dev->dev);
2185 
2186 clr_wakeup_capable:
2187 	if (i2c_dev->wakeup_src)
2188 		device_set_wakeup_capable(i2c_dev->dev, false);
2189 
2190 	if (i2c_dev->dma) {
2191 		stm32_i2c_dma_free(i2c_dev->dma);
2192 		i2c_dev->dma = NULL;
2193 	}
2194 
2195 fmp_clear:
2196 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2197 
2198 clk_free:
2199 	clk_disable_unprepare(i2c_dev->clk);
2200 
2201 	return ret;
2202 }
2203 
2204 static int stm32f7_i2c_remove(struct platform_device *pdev)
2205 {
2206 	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
2207 
2208 	stm32f7_i2c_disable_smbus_host(i2c_dev);
2209 
2210 	i2c_del_adapter(&i2c_dev->adap);
2211 	pm_runtime_get_sync(i2c_dev->dev);
2212 
2213 	if (i2c_dev->wakeup_src) {
2214 		dev_pm_clear_wake_irq(i2c_dev->dev);
2215 		/*
2216 		 * enforce that wakeup is disabled and that the device
2217 		 * is marked as non wakeup capable
2218 		 */
2219 		device_init_wakeup(i2c_dev->dev, false);
2220 	}
2221 
2222 	pm_runtime_put_noidle(i2c_dev->dev);
2223 	pm_runtime_disable(i2c_dev->dev);
2224 	pm_runtime_set_suspended(i2c_dev->dev);
2225 	pm_runtime_dont_use_autosuspend(i2c_dev->dev);
2226 
2227 	if (i2c_dev->dma) {
2228 		stm32_i2c_dma_free(i2c_dev->dma);
2229 		i2c_dev->dma = NULL;
2230 	}
2231 
2232 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2233 
2234 	clk_disable_unprepare(i2c_dev->clk);
2235 
2236 	return 0;
2237 }
2238 
2239 static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev)
2240 {
2241 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2242 
2243 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
2244 		clk_disable_unprepare(i2c_dev->clk);
2245 
2246 	return 0;
2247 }
2248 
2249 static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev)
2250 {
2251 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2252 	int ret;
2253 
2254 	if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
2255 		ret = clk_prepare_enable(i2c_dev->clk);
2256 		if (ret) {
2257 			dev_err(dev, "failed to prepare_enable clock\n");
2258 			return ret;
2259 		}
2260 	}
2261 
2262 	return 0;
2263 }
2264 
2265 #ifdef CONFIG_PM_SLEEP
2266 static int stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
2267 {
2268 	int ret;
2269 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
2270 
2271 	ret = pm_runtime_get_sync(i2c_dev->dev);
2272 	if (ret < 0)
2273 		return ret;
2274 
2275 	backup_regs->cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
2276 	backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
2277 	backup_regs->oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
2278 	backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
2279 	backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR);
2280 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
2281 
2282 	pm_runtime_put_sync(i2c_dev->dev);
2283 
2284 	return ret;
2285 }
2286 
2287 static int stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
2288 {
2289 	u32 cr1;
2290 	int ret;
2291 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
2292 
2293 	ret = pm_runtime_get_sync(i2c_dev->dev);
2294 	if (ret < 0)
2295 		return ret;
2296 
2297 	cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
2298 	if (cr1 & STM32F7_I2C_CR1_PE)
2299 		stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
2300 				     STM32F7_I2C_CR1_PE);
2301 
2302 	writel_relaxed(backup_regs->tmgr, i2c_dev->base + STM32F7_I2C_TIMINGR);
2303 	writel_relaxed(backup_regs->cr1 & ~STM32F7_I2C_CR1_PE,
2304 		       i2c_dev->base + STM32F7_I2C_CR1);
2305 	if (backup_regs->cr1 & STM32F7_I2C_CR1_PE)
2306 		stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
2307 				     STM32F7_I2C_CR1_PE);
2308 	writel_relaxed(backup_regs->cr2, i2c_dev->base + STM32F7_I2C_CR2);
2309 	writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1);
2310 	writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2);
2311 	stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
2312 
2313 	pm_runtime_put_sync(i2c_dev->dev);
2314 
2315 	return ret;
2316 }
2317 
2318 static int stm32f7_i2c_suspend(struct device *dev)
2319 {
2320 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2321 	int ret;
2322 
2323 	i2c_mark_adapter_suspended(&i2c_dev->adap);
2324 
2325 	if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) {
2326 		ret = stm32f7_i2c_regs_backup(i2c_dev);
2327 		if (ret < 0) {
2328 			i2c_mark_adapter_resumed(&i2c_dev->adap);
2329 			return ret;
2330 		}
2331 
2332 		pinctrl_pm_select_sleep_state(dev);
2333 		pm_runtime_force_suspend(dev);
2334 	}
2335 
2336 	return 0;
2337 }
2338 
2339 static int stm32f7_i2c_resume(struct device *dev)
2340 {
2341 	struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
2342 	int ret;
2343 
2344 	if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) {
2345 		ret = pm_runtime_force_resume(dev);
2346 		if (ret < 0)
2347 			return ret;
2348 		pinctrl_pm_select_default_state(dev);
2349 
2350 		ret = stm32f7_i2c_regs_restore(i2c_dev);
2351 		if (ret < 0)
2352 			return ret;
2353 	}
2354 
2355 	i2c_mark_adapter_resumed(&i2c_dev->adap);
2356 
2357 	return 0;
2358 }
2359 #endif
2360 
2361 static const struct dev_pm_ops stm32f7_i2c_pm_ops = {
2362 	SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend,
2363 			   stm32f7_i2c_runtime_resume, NULL)
2364 	SET_SYSTEM_SLEEP_PM_OPS(stm32f7_i2c_suspend, stm32f7_i2c_resume)
2365 };
2366 
2367 static const struct of_device_id stm32f7_i2c_match[] = {
2368 	{ .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup},
2369 	{ .compatible = "st,stm32mp15-i2c", .data = &stm32mp15_setup},
2370 	{},
2371 };
2372 MODULE_DEVICE_TABLE(of, stm32f7_i2c_match);
2373 
2374 static struct platform_driver stm32f7_i2c_driver = {
2375 	.driver = {
2376 		.name = "stm32f7-i2c",
2377 		.of_match_table = stm32f7_i2c_match,
2378 		.pm = &stm32f7_i2c_pm_ops,
2379 	},
2380 	.probe = stm32f7_i2c_probe,
2381 	.remove = stm32f7_i2c_remove,
2382 };
2383 
2384 module_platform_driver(stm32f7_i2c_driver);
2385 
2386 MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
2387 MODULE_DESCRIPTION("STMicroelectronics STM32F7 I2C driver");
2388 MODULE_LICENSE("GPL v2");
2389